Valve



(No Model.)

H. T. CLARKE. REVERSING VALVE.

No. 456,886. Patented July 28, 1891.

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UNITED STATES PATENT OFFICE.

HARRY T. CLARKE, OE PORTLAND, OREGON, ASSIGNOR TO `THE PORTLAND IRONVORKS, OF SAME PLAGE.

REVERSlNG-VALVE.

SPECIFICATION forming part of Letters Patent No. 456,886, dated July 28,1891..

Application filed April 1, 1891. Serial No. 387,285. (No model.)

To all whom it may concern:

Be it known that I, HARRY T. CLARKE, a citizen of the United States,residing at Portland, in the county of Multnomah and State L; of Oregon,have invented a new and useful Improvement in Reversing-/Talves, ofwhich the following is a speccation, reference being had to theaccompanying drawings, forming a part hereof.

The object of my invention is to overcome the objectionable features ofthe reversingvalves heretofore in use in twin engines intended to beconstantly reversed.

The essential features, in addition to the usual requirement-s, of avalve designed to accomplish such continuous reversing are a shortstroke or movement, an absolute steamtight fit of the valve on its seat,so that the same will completely throttle the steam when set on `itsneutral point, while at the same time the valve must move freely so asto be easily controlled and be quick to respond to the hand of theoperator. If the valve has too long a stroke or movement, or does notmove easily, its action, of course, is not under control, and it is thenan annoyance to the operator such as will retard the work on hand;While, if the reversing-valve does not t absolutely steam-tight, theefficient working of the engines is lost, the distribution of the livesteam is no longer under complete control, and such a defect isnecessarily attended with imminent danger, for, should the live steamleak into either of the ports of the engines while the same are at astandstill, the engines might be caused to start up suddenly andthreaten life and limb. These are some of the common defects fou nd inreversing-valves, and to remedy the same I construct my reversing-valveas shown in the drawings, in which- Figure l is a side elevation showingmy invention combined with the main valves B and piston-cylinders A, ofwhich an end View is seen. Fig. 2 is a partial sectional view on theline y y of Fig. 3, also showing a sectional view of one of the mainvalves B used in conjunction with my invention, and Fig. 3 is a partialvertical section of my invention.

Like letters and figures refer to like parts.

C is the valve-chamber, mounted by means the glands of the flanged endsl of the steam-conducts b b on the flanged top of the steam-supply pipesc c, leading from the ports 9 10 of the main valves.

(Z is the steam-inlet to the steam-chamber e, connecting the steampassage-waysff, constituting the cylindrical seats for the steanrbalanced piston-valves g, sliding over the ports z.. The construction ofthe latter is as 6c appears, merging from a pipe end k3 into asemi-globn1ar form 4, and thence into a concave rectangle,so as toextend half-way around the valve and thus afford a sufficient steamarea.The piston-valves g are rendered absolntely tight by being provided withsnaprings 5, said rings being prevented from slipping into the ports hby providing bridges o.

My reversing-valves operate at right angles to the `main valves, thelatter being hollow 7o cylindrical slide-valves t', operated from asingle shaft. 'lhe valve-stems 7 extend through 7i: is theexhaust-passage connecting the steam passage-way or cylindricalvalve-seats ff with the exhaust-conduct S. The valve-stems '7 areconnected by suitable connections with a T-crank'm, pivotally supportedon a fulcrum n, thus affording suitable means for moving saidreversing-valves g simultaneously in opposite directions. The 8 actionof the said reversing-Vabres g is apparent. As seen in the drawings, thevalve there shown is placed at its neutral point. Operating the T-crankm in either direction would cause said valve to clear the port h,givingthe 8 5 steam either ingress or egress, and the movement of theother valve would be reciprocal, with an opposite effect. In reversingthe en` gines, the live steam is thus first gradually cut off and thengradually readmitted into 9o the desired port.

Having described my invention now, what I claim, and desire to secure byLetters Patent, is-

l. The combination of the main valves of twin-cylinder engines withreversing-valves constructed as described, consisting substantially of avalve-chamber C, the steam-conducts b b of which are connected with theports of said main valves, the said valve- 10o chamber O being providedwith a steam-cham ber e and steam passage-ways or cylindrical providedwith a steam-chamber e and steam passage-Ways or cylindrical valve-seatsff', connected thereby on one end, and connected on `the other end by anexhaust-chamber 7c with the exhaust-conduct 8, the ports h, bridges o,steam-tight balanced piston-valves g, and means for operating thelatter, substantially as and for the pn rposes set forth.

HARRY T. CLARKE.A

Witnesses:

G. G. AMES, T. J. GEISLER.

